The invention generally relates to an airbag and more particularly one which contains a baffle for trapping particulates.
The purpose of an airbag is to protect a vehicle occupant during an automobile crash. As is known in the art, an airbag can be located virtually on any part of the vehicle. Airbags that are utilized to protect the driver are usually installed in the steering wheel, while the airbags that are utilized to protect the front passenger are installed in the instrument panel.
A gas-producing device such as a pyrotechnic inflator typically inflates a driver side airbag. A pyrotechnic inflator generally comprises a solid generant to generate inflation gas. At the onset of a crash, the gas generant bums producing inflation gas, which is used to fill a vehicle airbag.
The gas generating composition must bum very rapidly to inflate toil the airbag, for example in 30 milliseconds or less, but the bum rate must be controllable and reproducible to ensure airbag deployment and inflation in the required time, location, and configuration. Since the gas generant must bum very rapidly to inflate the airbag, the produced inflation gases may reach temperatures of about 590xc2x0 C. or higher. These high temperature gases may be detrimental to the integrity of the airbag fabric.
Another problem associated with pyrotechnic inflators is the occurrence of burn holes in the airbag from hot particulates within the inflation gas. The particulates can originate from unburned gas generant or from solid combustion particles. The solid particles or what is generally referred to as xe2x80x9cslagxe2x80x9d or xe2x80x9cclinkersxe2x80x9d are formed by the combustion of gas generants containing metallic compositions. A filter is generally utilized to remove the particulates from the inflation gas, thereby preventing the particulates from entering into the airbag. There is a chance that some particulates will pass through the filter in the inflator into the airbag. These particulates are extremely hot and they tend to stick to the interior of the inflatable cushion, and because the airbag is typically made from nylon or another fabric, the hot particulates can cause small holes to appear in the cushion. This might release the hot inflation gas potentially affecting the inflation profile of the airbag.
U.S. Pat. No. 6,283,499 B1 teaches an airbag device having an inner bag, disposed in between the outer bag and the inflator, wherein the inner bag is made of a flexible material and protects the outer bag from hot gases and particles emanating from the inflator.
In the present invention, an airbag comprises an inflatable cushion, a heat shield, and a baffle. The heat shield and the baffle are preferably made from a different material than the inflatable cushion. The baffle contains a baffle opening and this opening provides an inflation gas passageway from the baffle to the inflatable cushion. The baffle opening is aligned with approximately one-half of the inflator opening and has an area that is approximately equal to the area of the inflator opening.